A conventional distributed antenna system (DAS) provides indoor or outdoor coverage for wireless communications. Transmitted power is divided among several antennas in distributed locations so as to provide a large coverage area using less transmitted power than would be required by a single antenna system. The antennas of a typical DAS are connected to a cellular base station and are used for cellular mobile communications.
It can be desired to locate a mobile device within a DAS, for example, for emergency purposes (e.g., 911 calls). However, because the received signals from the distributed antennas are typically combined in the uplink to the base station receiver, the base station has no ability to determine which of the distributed antennas is closest to the transmitting mobile device.